Turbo, SIM Toolkit. What does it mean?
Insert Turbo into the phone and you can use various applications.

Applications? Why, what for?
For example you can store text messages on removable memory card and have huge
SMS archive. Or use encrypted messages and be sure about your
privacy.
Or mask incoming messages against enemy.
You can store texts on the memory card as well.
And locate friends. And keep secrets. And many other things.

And next?
Turbo can be also used for
remote control and measurement. There are several universal ports, interfaces and A/D converters available on the connector.
It is trivial to connect for example alarm or thermometer.

Anything else?
Also you can write your own applications. The GNU development tool chain
is open source, free software. We have published all the source code of our
applications and do our best with documentation and providing many examples.